Portable spa with shell weightline



FIG. 1 is a perspective view of a portable spa of the invention, showing a shell having a weightline in a sidewall of the shell;

FIG. 2 is an elevated perspective view of the portable spa of FIG. 1, showing the shell and weightline; and,

FIG. 3 is a top view of the portable spa of FIG. 1, showing the shell and weightline.

Broken lines in the Figures form no part of the claimed design. 

I claim the ornamental design for a portable spa with shell weightline, as shown and described. 